Method of eliminating soot



May '23, 1933.

R. A. BLUNT METHOD OF ELIMINATING SOOT Filed March 51, 1927 fl-za 2; 15E 117%;

J] 14 n I n n n 16 INVENTOR #qyden 14. 6/0/77.

BY WT m ATTORNEY Patented May 23, 1933 UNITED STATES} ROYDEN A. BLUNT,or BALTIMORE; MARYLAND METHOD OF ELIMINATING SOO'I" Application filedMarch 31, 1927. Serial No. 180,050.

This invention relates to the art of fuel burners and more specificallyto a method of and apparatus for removing deposits of soot in gasproducer lines.

It has heretofore been customary to remove accumulations of soot byraking out or blowing out with steam, but both of these methods areobjectionable, since raking out is difficult and expensive and stillleaves the ultimate elimination of the soot to be pro vided for, andblowing out with steam discharges the soot into the atmosphere unburnedwith a consequent pollution of the surrounding territory.

By my present invention I introduce a large volume of low pressure airwhich burns the soot progressivelyfrom the point of intake of the blowerair up to the end of the line, and results in the combustion ofsubstantially all of the soot by the time the top of the stack isreached. During this operation a very high heat is generated and it isnecessary to carefully regulate the volume of air so as to providesufficient oxygen'for complete combustion, and at the same time regulatethe pressure so as not to propel the soot into the atmosphere unburned,and not to generate such a great degree of heat that the metal andrefractory parts of the sys tem will be damaged.

It is therefore an object of this'invention to provide a new andimproved method of soot elimination.

It is another object of this invention to provide an apparatus forcarrying out this method. r

It is also an object of this invention to perform these operationswithout discharging the soot into the atmosphere unburned and 0 withoutdamaging the gasma-in. g

It is another object of my invention to perform the burning outoperation without shutting down the operation of the furnaces or lehrswhich are ordinarily heated by :the

5 producer gas, and to cool the main'a's the burning out is beingeffected.

lVith the above and other objects in view, which will be apparent as thedescription proceeds, I have set forth my invention in the followingspecification taken inconnection with the accompanying drawing, inwhich:- I

Fig. 1 is a diagrammatic plan view of my improved apparatus, and

Fig. 2 is a vertical section through a portion' of my apparatus on theline 2-2 of Fig. 1, on an enlarged scale.

My invention is particularly adapted for the. removal of products ofcombustion from producer gas mains. In these there is a heavyaccumulation of soot, which is of a loose, light and flaky nature, sothat it is easily blown out into the atmosphere if any considerablepressure is applied to it. This accumulation is so rapid that afteroperation for a week the mains are often filled with it to one-third oftheir capacity, thus impairing the efficiency of the gas main and makingit necessary to remove'this accumulation. I- have discovered that thiscan be done, without discharging thesoot into the atmosphere, andwithout damaging the line, by using a large volume of low pressure air.While the Volume and pressure vary for difierent installations, andespecially with the length thereof, I have found that a volume of fromfortylto fifty thousand cubic feet of air per minute, and a pressure ofthree-fourths of an inch of water,-aresatisfactory for most purposes,and particularly for installations using mains of 6 to 8 feet diameterand 700 or 800 feet in length with several outlets therefrom. If apressure greater than one and one-half inchesof water is used, thetemperature which is'generated by the com 8 bustion of the soot isordinarily so great that the metal and refractory parts of the producerlines are damaged;

. Referring to the accompanying drawing, Ihave illustrated therein thegeneral arrangement-of aproducer gas main 10 and a series of furnaces 11and lehrs 12 heated by the producer gas conveyedby said main. Each ofthe furnaces and lehrs is provided with a cut-off damper 13, to preventcommunication between them and the main at predetermined.times,and eachof the furnacesand lehrs is 'also provided with gas or oil burners 14for heating them independent ly of the producer gas 1 during theburningburned out, with the resut out period. At suitable points in theline, stacks 15 communicate with the atmosphere and each of these stacksis preferably provided with a cut-off damper 16 adjacent to itsconnection with the main 10. The producer gas is supplied to the main at17 from any suitable gas producer, or gas producers (not shown), and themain may be shut off from the latter by a damper 18.

The air is supplied by a blower fan 21, of any well known type capableof handling a large volume of low pressure air, which is connected withone end of the producer main. 1

When a sufficient amount of loose soot has accumulated in the latter towarrant its removal, the dampers communicating with the producers,furnaces and lehrs are closed, the dampers communicating with the stacksare either left completely open or partially th-rottled, as will beexplained later, and the blower is started at such arate that it willdeliver from 40,000 to 50,000cubic feet of air per minute at a pressureof approximately of an inch to 1 inches of water, The

incoming air starts the hot soot rolling along the main and thecombustion begins to take place without the application of any enternalheat. This generates additional heat and the burning out is progressivethroughout the main, succeeding portions of the incoming air furnishingthe necessary oxygen for the combustion of'the soot contained insucceeding portions of themain and eifectin'gv a cooling of thoseportions of the main from which the soot has reviously been thatsubstantially' all of the soot in the main is gradually burned before itcan emerge from the stack. Inasmuch as the sootis, practically purecarbon, no residue is left,

A-sufficient volume of air must be introduced tolcarry all the sootalong withtit me toprovide sufiicient oxygen to promote the combustionof all of the soot. At the same time the air pressure must: be lowenough to prevent blowing the loose, flaky soot into the atmosphereunburned. The volume of air introduced can be controlled at the blow erby regulating its speed and by'throttling it by a slide control 22, TThis regulation of'the volume of air at the blower also affects thepressure devel-- oped in the line. Consequently, if too great a pressureis being developed, it can be re duced bypartially throttling theblower; A similar reduction in the pressure can also be accomplished byopening the stack dampers. H a V The temperature developed in the mainincreases with the volume and pressure, and with the length of the main,and is highest at the end farthest from the inlet of the blower air. Ithasbeen-foun'd that in along main a pressur-e1of asmuch as 1 inches ofwater, coupled with a volume of from 40,000 to 50,000 cubic feet of airper minute, will develop a temperature of approximately 2800 F., whichis sufliciently high to cause gradual deterioration of the gas main byopening up seams therein, by burning the metal framework, and bybreaking down the efficiency of the refractory parts. I have thereforefound it desirable, when using the above volume of air in a long main,such as that described above and illustratedherein, to reduce thepressure to of an inch of water, and I have found that this ean be mosteffectively done by throttling the blower and leaving the stack damperswide open.- Under these conditions-a'temp'erature of from 2=l00 to 2500F J is developedat the hottest period.

I have found that in such installation the soot can be effectivelyremoved by burning out themain in the manner indicated here-- in for aperiod of about 45 minutes per week.- During the burning out it is notnecessary toshut down the operation of the furnaces and lehrswhich arenormally heated by the producer gas, as their operation can be continuedby lighting the gas or oil burners 1 f.

I have also foundcthat when excessive temperatures are developed atvarious points in the line, these temperatures can be lowered byinjecting small amounts of steam into that portion of the line, as bythe nozzles This steam acts as a cooling agent and absorbs the excesssensible heat."

In Fig. 2'1 have shown the construction of one form of gas producer.main. This consists of a steel shell 31, immediately inside of which isplaced a lining of sil-o cel bricks 32, and inside of the latter isplaced a lin ing of fire bricks 33 The sil-o cel bricks and therefractory bricks are each luted to gether in the regular manner.

By the termhot soot, as used herein, I mean that the soot is at thetemperature of its'ignition. V I V I c I From the above description itwill be apparent that I have solved the difiicultproblem of disposingof'loos'esoot, whichiisan inherent disadvantage in the use of pro ducergas, without discharging this soot into the atmosphere unburned, thusmaking it; possible for'industries located in cities, ,aswell as thosein rural districts, to avail themselves of this cheap sourceVo-f fuelwithout conflict with the municipal regulations on soot disposal, andvthat the burning out roporation may be carried on simultaneously withnornial production in the factory in which the burning out is tobeeffected, thus resulting in a considerable saving of time andmoneyr Itwill also be obvious that IIIYlHVGBlll'JlOH can be applied with equalefficiency to shorterpandless complicated mains than that illustratedand described herein, and that the connections and arrangement of theVarious parts of my apparatus may be varied in many ways Within thescope of the following claims.

I claim:

1. The method of eliminating loose hot soot at the temperature ofignition in the presence of air from gas producer mains, which comprisesblowing into the main over 40,000 cubic feet of air per minute at apressure of less than 2 inches of Water, and thereby burning the sootWithin the main Without discharging it into the atmosphere.

2. The method of eliminating loose hot soot at the temperature ofignition in the presence of air from gas producer mains, which comprisesblowing into the main from 40,000 to 50,000 cubic feet of air per minuteat a pressure of approximately of an inch of Water, and thereby burningthe soot Within the main Without discharging it into the atmosphere.

ROYDEN A. BLUNT.

